This invention relates generally to equipment used in producing fluid from a well and more particularly concerns tools to enhance the operation of downhole reciprocating pumps.
U.S. Pat. No. 6,068,052, issued to the present inventor on May 30, 2000, explains the common practice and problems of “tapping” and discloses a no tap tool for downhole reciprocating pumps. That tool eliminates the need for “tapping” in the operation of a downhole pump, reduces the unidirectional application of force to the plunger of a downhole pump and allows the plunger to take the path of least resistance to overcome a “stuck” condition.
The tool is connectable between the last sucker rod of the sucker rod string and the downhole pump. A cylinder with a closed end and an internal annular seat proximate an open end houses a piston which reciprocates slidably within the cylinder and is free to rotate within the cylinder. The tool components are concentric about the longitudinal axis of the tool, so the tool components are independently free to rotate about the tool axis, allowing the plunger of the pump to rotate to the path of least resistance to achieve its freedom, thereby further reducing the forces exerted on the system components.
The freedom of the tool components to independently rotate is one of the keys to the success of this “old” tool. However, because of this freedom of the tool components to independently rotate, use of the tool in the string renders the tool and any of the equipment downhole of the tool irretrievable without retrieval of all of the equipment downhole of the tool.
It is, therefore, an object of this invention to provide a no tap tool which affords the benefits of the “old” tool. To this end, it is also an object of this invention to provide a no tap tool which utilizes independently rotating components. But, it is a further object of this invention to provide a no tap tool which does not prevent retrieval of equipment downhole of the tool.
While the invention will be described in connection with a preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.